Lifting jack

ABSTRACT

This is a lifting jack particularly adapted for use in erecting farm silos and specifically embodies a cam slot and pin arrangement for producing a pre-determined increment of rotation of the silo structure during each elevating operation.

United States atent 1 1 1 1 Tegtmeier 1 Dec. 16, 1975 [5 LIFTING JACK 3,182,958 5/1965 Peterzon-Arbella 254/89 H tor: Sheldon D- Tegtme er, Colfax, N- 3,554,49i H1971 Tegtmeier 2.54/1

Dak. FOREIGN PATENTS OR APPLICATIONS [73] Assignee: Tegtmeier & Sons, Inc., West Fargo, 783,915 10/1957 United Kingdom 254/89 H N. Dak.

22 i Apt 2 1975 Primary ExaminerOthell M. Simpson Attorney, Agent, or Firm-John W. Adams [21] App]. No.: 564,470

52 vs. C]. 254/89 R; 254/89 R [57] 1 ABSTRACT [51] Int. Cl. B66F 7/12 This is a lifti jack particularly adapted f use i Fleld 0f Search R, H, erecting fa m ilos and pecifically embodies a cam 4 4 B, 4 c slot and pin arrangement for producing a predetermined increment of rotation of the silo structure [56] References Cited during each elevating operation.

UNITED STATES PATENTS 2,993,679 7/1961 Morgan 254 89 R 3 10 Drawmg Fgures US. Patent Dec. 16, 1975 Sheet 1 of3 3,926,411

FIG.3

US. Patent Dec. 16,1975 Sheet 2 of3 3,926,411

;ooooooo FIG. 7

US. Patent Dec. 16, 1975 Sheet 3 of3 3,926,411

LIFTING JACK The lifting jack mechanism embodied in this invention is generally similar to that disclosed and claimed in the prior U.S. Pat. No. 3,554,491 issued Jan. 12, I971 to Roger Tegtmeier. That mechanism, however, did not have any means for providing any rotation of the silo structure during the lifting operation. The silo section panels most often used in recent years are of steel construction with a protective coating of fused-on glass or ceramic material and are connected at their marginal edges by overlapping the same with adjacent panels. The lift plates for connecting the jack mechanism and the silo structure are attached to the silo panels at the overlapped vertical seams by means of attaching pins or bolts and the vertical seams are offset circumferentially from the adjacent rows of panels above and below so that these vertical seams will be out of vertical alignment, as shown in FIG. 1 and thus provide maximum sidewall strength. Since the base of each lifting jack is in fixed stationary position during the erection operation, it is necessary that the silo structure be rotated during each lift in order to align the vertical seams of the panels in the next lower row of sections with the fixed position of the respective jacks and thus provide the desired offset vertical seam relationship without moving the jack units circumferentially within the silo structure each time a new row of panels is attached and elevated.

It is an object of the present invention to provide a silo lifting jack mechanism which embodies means for producing an increment of rotation during each stage of the lifting operation.

More specifically it is an object to provide a jack attaching lift plate provided with sloping cam slots within which pins for attaching said plates to the silo panels are slidably mounted to produce the desired increment of rotation of the silo structure during each individual lifting operation.

These and other objects and advantages of this invention will more fully appear in the following description made in connection with the accompanying drawings in which like reference characters refer to similar parts throughout the several views, and in which:

FIG. 1 is a perspective view of a portion of a silo being erected;

FIG. 2 is a fragmentary vertical sectional view taken substantially along the line 2--2 of FIG. 1;

FIG. 3 is front elevational view of one of the supporting cradles, per se.;

FIG. 4 is a vertical sectional view through said cradle;

FIG. 5 is a vertical sectional view of a portion of the silo shown in FIG. 1 showing a pair of typical lifting jacks attached thereto;

FIG. 6 is a fragmentary inside elevational view of the jack attaching lift plates showing the same attached to a silo panel and showing the same in elevated position by dotted lines;

FIG. 7 is a vertical sectional view taken substantially along the line 77 of FIG. 6;

FIG. 8 is a horizontal sectional view taken substantially along the line 88 of FIG. 7;

FIG. 9 is an elevational view showing the lower portion of one of the jacks; and

FIG. 10 is a side elevational view of the structure shown in FIG. 9 with an attaching lift plate and silo portion shown in attached position by dotted lines.

As previously stated, the lifting mechanism and stablizing structure is similar to that disclosed in said prior US. Pat. No. 3,554,491 granted to Roger Tegtmeier.

A portion of a typical silo designated by the letter S, is illustrated in FIG. 1. The silo is mounted on a circular base or curb B with a base ring 33 on which a plurality of supporting cradles C are mounted to provide temporary support for the bottom of the silo structure at certain stages of the erection operation. The silo is constructed of a plurality of circumferential rows or rings of panels 8. The lower edge portion of each row is received within the upper edge portion of the next adjacent upper row as shown in FIG. 1. The panels have apertures therethrough to facilitate bolting the same together in overlapped relation. The vertical edges of adjacent panels are also overlapped and bolted together as illustrated.

Each jack mechanism includes a chain 10a, upper sprocket 10b and a lower sprocket 100. A center supporting column in the form of an upstanding channel member 1 l is mounted on a suitable jack base 12 which rests on the concrete floor surface inside the silo curb B. The supporting channel 11 has a pair of flanges 1 1a and a central web portion 11b. The upper sprocket 10a is joumaled on a pair of pillow blocks 13 fixed to the top of the channel 11. The lower sprocket 10c is mounted between the flanges 11a in a cut-out window or opening 11c in the lower portion of the web 11b above the base 12. The lower sprocket 10c is driven by the output shaft 14 from a gear box 15. An electric motor 16 provides the driving power for said shaft 14 through said gear box. The outer run of the chain 10a has two pairs of vertically spaced mounting sleeves 20 carried by a mounting plate 21 which is connected to said chain as by the bolts 22. A lift plate 25 has two pairs of vertically spaced mounting pins 26 which are respectively received in the sleeves 20 to connect the lift plate 25 to the chain 10a. The lift plate 25 has a plurality of cam slots 27 therein and connecting pins 28 are mounted in each of the cam slots 27 and extend through the apertures in the vertical marginal edge portions of the overlapped panel sections to connect said panel sections to said lift plates 25. Each of the connecting pins 28 is provided with a rotatable bushing 29 joumaled thereon to facilitate shifting movement of the bushings and pins within the cam slots as will be described hereafter.

The upstanding chain and sprocket assembly 10 and the fixed upstanding supporting channel 11 are stabilized by means of a diagonal strut member 30 connected at its upper end to the channel member 11 and at its lower end to a central anchoring member 31. This strut member has two telescopically adjustable elements to facilitate adjustment for different diameter silos.

The first ring of the panel sections 8 is bolted together in the conventional manner to form a complete circular ring unit. The jacks are connected at each vertical seam inserting the connecting pins 28 through aligned holes at each seam of adjacent panels, the panel connecting bolts having been omitted from these holes. The bushings 29 rotatably surround the pins 28 and are received in the respective cam slots 27 as best shown in FIG. 8. The lift plate 25 is connected to the chain 10a by inserting the two pairs of mounting pins 26 into the respective mounting sleeves 20. When all of the jacks have been connected, the lift motors 16 for all units are simultaneously energized and the assembled ring pan- I the cam slots 27 will be initially elevated with respect to the respective bushings 29 which will be shifted to the bottom of the cam slots 27 and thus produce the desired increment of rotation of the assembled silo sections being supported and elevated by said jacks as shown by the dotted lines in FIG. 6. The jack units sup port the assembled silo sections in elevated position when the plates 21 and reach the top of the inner run of the chain and the panels of the next circumferential ring are attached to the bottom ring of elevated panels and are securely bolted together with the lower edges of the panels 8 supported on the cradles 32 which are securely anchored to the outside of base ring 33 which surrounds the concrete base B of the silo. When the lower ring of panels has been completely assembled and bolted to the next adjacent upper ring of panels to become a part of the fully assembled silo section, the jack units are lowered so that the plates 25 can be removed for reattachment to intermediate portions of the bottom newly assembled ring of silo panels which are of course supported in the cradles 32 during the operation of reattaching the plates for the next lift.

It will be seen that l have provided a relatively simple yet highly efficient mechanism for lifting assembled silo sections to facilitate construction of a silo unit while providing means for rotating the assembled silo portion during each lifting operation in order to offset the vertical seams of the bolted-together wall panels 8 of the silo;

It will, of course, be understood that various changes may be made in the form, details, arrangement and proportions of the parts without departing from the scope 4 of this invention which is defined by the appended claims.

What is claimed is:

1. An elevating jack system for erecting storage silos comprising a plurality of elevating mechanisms adapted to be supported by the base platform of the silo structure and including means for laterally stabilizing said mechanisms during the erection operation,

each elevating mechanism including:

a jack attaching lift plate which includes a plurality of inclined cam slots,

a plurality of attaching pins slidably mounted in said cam slots and removably connecting each lift plate to assembled portion of the silo structure, and

means for attaching said lift plate to the respective elevating mechanisms to simultaneously lift all portions of the silo into elevating position while simultaneously rotating the same through a predetermined arc to permit assembly of the next row of silo panels thereunder.

2. The structure set forth in claim 1 and each elevating mechanism having a plurality of attachment sleeves connected therewith, and

a plurality of depending pins fixed to each of said lift plates and positioned to be received in said sleeves for connecting each elevating mechanism to the lift plate.

3. The structure set forth in claim 1 and each of said camming pins including a roller bushing rotatably mounted thereon and slidably received within the cam slots to facilitate sliding movement therein. 35 

1. An elevating jack system for erecting storage silos comprising a plurality of elevating mechanisms adapted to be supported by the base platform of the silo structure and including means for laterally stabilizing said mechanisms during the erection operation, each elevating mechanism including: a jack attaching lift plate which includes a plurality of inclined cam slots, a plurality of attaching pins slidably mounted in said cam slots and removably connecting each lift plate to assembled portion of the silo structure, and means for attaching said lift plate to the respective elevating mechanisms to simultaneously lift all portions of the silo into elevating position while simultaneously rotating the same through a predetermined arc to permit assembly of the next row of silo panels thereunder.
 2. The structure set forth in claim 1 and each elevating mechanism having a plurality of attachment sleeves connected therewith, and a plurality of depending pins fixed to each of said lift plates and positioned to be received in said sleeves for connecting each elevating mechanism to the lift plate.
 3. The structure set forth in claim 1 and each of said camming pins including a roller bushing rotatably mounted thereon and slidably received within the cam slots to facilitate sliding movement therein. 